Lift Weights to Stoke Your Metabolic Fire!

Written by Shoshana Pritzker Monday, 17 May 2010 17:43

By Thomas D. Fahey, Ed.D

 

Losing fat should be simple— take in fewer calories in your diet than you use during metabolism or exercise and the pounds will melt away.  Unfortunately, your body tries to keep you at a constant weight; it’s called your weight set-point. If you go on a weight loss diet, your body’s weight control center makes you hungry and slows down your metabolism, which makes you gain back the weight you lost. Fortunately, you can change your weight set-point by increasing muscle mass. The best way to add muscle is to lift weights.

Avoid the Trap

Muscles are incredibly active tissues. At rest, they burn calories continuously. When muscles contract, they really turn up the heat. During exercise, muscle metabolism can increase as much as 15-20 times above rest. Scientists, using a technique called direct calorimetry, found that the body’s heat-generating capacity is directly proportional to muscle mass. The more muscle you have, the greater your metabolic rate. The best way to stoke your metabolic fire is to add muscle and then keep your new tissue active.

There are right and wrong ways to lose weight. Think of what happened to your girlfriend after she lost 20 or 30 pounds. Did she look healthy and athletic, or did she appear gaunt and drawn with a lot of excess skin? Probably, she looked terrible. She looked more like a patient with anorexia than the picture of health. And to make matters worse, she probably gained all the weight back and then some within six to eight months.

Her problem: A good portion of her lost weight was muscle tissue. Losing muscle slows metabolism, which makes it difficult to maintain fat loss. She dug herself in an energy deficit hole that made weight gain inevitable. Don’t fall into the same trap that your girlfriend did. Build muscle through weight training, and you will find it much easier to lose weight and keep it off.

Yo-Yo Dieting: Uh Oh!

Many women spend their lives on yo-yo diets— endless cycles of losing weight and gaining it back again. These women are suckers for any crackpot diet that comes along. Sometimes they restrict calories, other times fat, and still other times carbohydrates. In the short run, these women usually lose some weight, but they usually gain back what they lost and more.

Americans are clearly losing the “battle of the bulge.” Recent studies by the Centers for Disease Control and Prevention (CDC) showed that over 50 percent of Americans are obese or overweight. What is most alarming is that the population obesity rate has increased a whopping 50 percent since 1991. While we don’t totally understand the reasons for the obesity explosion, lack of exercise and excess calories in the diet are at the core of the problem.

 

PHAT (Pretty Hot and Tempting) Instead of Fat

When are the busiest times of the year in the gym? Right after the New Year and a month or two before summer. Why? Because people want to lose fat so they can look better. After the New Year, they have to make amends for a month of porking out. Just before summer, they realize that they will soon have to display their Moby whale bodies on the beaches of the world. Sure, they want to be healthier, but health takes a back seat to looks every time. If they can combine good health and looks— all the better.

Caloric restriction (usually without exercise) is by far the most popular weight loss strategy in America. Unfortunately, people lose muscle mass as well as fat. Most studies show that if you lose 20 pounds from a weight-loss diet without exercise, nearly 30 percent of the weight loss will be from muscle.

Sure, you will have lost weight. But, have you gotten closer to your goal of looking better in a swimsuit or sexier in your clothes? Not by a long shot. More typically, you look like you just completed extended chemotherapy treatments.

What if you could lose weight but look better? That’s what you want, right? Scientific studies have shown that this is not only possible, but also probably the key to permanent weight loss. With the right diet and exercise program, you can maintain almost all your muscle mass, even when you lose substantial amounts of weight.

Dr. William Kraemer and colleagues from Penn State and Ball State Universities found that people who combined caloric restriction with a weight training and aerobic exercise program maintained muscle mass while making sizable improvements in strength, body composition and aerobic capacity. The study included three groups: Subjects who dieted but didn’t exercise; those who dieted and did aerobic exercise; and those who dieted and did aerobics and weight training. In 12 weeks, each group lost the same amount of weight— about 20 pounds. The big difference between groups was the amount of muscle lost. People who dieted without exercising lost nearly seven pounds of muscle. Interestingly, those who dieted and did aerobics lost over four pounds of muscle. Only the group that dieted while also lifting weights and doing aerobics maintained muscle mass. They lost only about 1/2 pound of muscle, even though they lost a substantial amount of body weight. The bottom line from this study: When you add weight training and aerobics to your weight loss program, you lose more fat and less muscle.

Not all studies agree with Dr. Kraemer’s research. Other investigators have shown that adding weight training to a weight loss diet program makes no contribution to maintaining muscle mass or improving overall body composition. Why was Dr. Kraemer’s group successful while other researchers came up empty handed? Kraemer’s study carefully controlled the exercise intensity, using personal trainers to make sure that people actually did the work.

Look around in any health club. Some people spend more time socializing than working hard. You can’t build muscle and lose fat by looking at yourself in the mirror or talking to your friend on the next machine. Push yourself when you do resistive or aerobic exercises. You don’t have to exercise for hours and hours, but you do need to be serious about your program.

 

The Joys of Muscle Mass

Until recently, health experts downplayed resistive exercise as an important component in a health promotion program. However, many recent studies have demonstrated that this type of exercise deserves a central place in your fitness and weight control program.

People with more muscle have a higher metabolic rate. While metabolic rate drops during rapid weight loss— regardless of whether you maintain muscle mass— over the long term, maintaining muscle mass seems to be the most important factor determining whether you can keep the weight off. As discussed, you are certainly going to look better if, after losing weight, you have maintained your muscle mass. People on “yo-yo” weight control programs tend to lose muscle during periods of weight loss and replace it with fat during periods of weight gain.

Muscle is critical for quality of life. People who lose a lot of muscle mass during their weight loss programs usually lose some fitness. They can’t do as much physically, so their performance declines when skiing, playing golf, hitting a tennis ball, or carrying groceries.

Muscle holds a lot of your body water and is essential for regulating body temperature. Losing muscle mass during a weight loss program robs your body of its precious water stores. Less body water means you will have more trouble regulating heat and body temperature. Muscle water loss also decreases your blood volume, which can impair endurance capacity.

Finally, muscle mass is critical to bone health. Many studies show that muscle and bone strength are highly related. Women lose bone mass with age. Maintaining muscle strength and mass helps prevent age-related bone mass loss and life-threatening fractures.

 

Final Frontier of Fat Management

Unfortunately, building muscle is not the magic bullet for weight management. It helps— a lot— but it’s not the total answer. Most studies, including Dr. Kraemer’s, show that you lower your metabolic rate whenever you lose weight; regardless of whether or not you maintain muscle mass. Maintaining muscle mass certainly prevents some, but not all, of the decrease. This has confused researchers and is the subject of intense study. If muscle mass is closely linked to metabolic rate, why is metabolism depressed even when you maintain muscle mass?

The answer lies in the complex genetic controls of body weight and fat stores. Your body maintains a balance in its tissues to survive. When you remove fat from fat cells, you disturb their balance. They initiate complex physiological control mechanisms to maintain the biological status quo. Over the short term, increased muscle mass cannot compensate fully for these natural controls. However, over the long term, the natural links between muscle mass and metabolic rate most likely reestablish themselves.

Certainly, from the standpoint of the primary directive of looking good in your clothes or swimsuit, losing fat while gaining muscle is the key. If you want to lose weight and improve your appearance, your direction is clear— eat less, but include weight training and aerobics in your program. If you don’t do resistive exercises while trying to lose weight, you are going to lose muscle mass and will not get the results you want.

 

Sample Weight Training Program for Weight Loss

Do at least one set of 10 repetitions of the following exercises. You will get even more benefits if you do two or three sets per exercise.

 

Exercise	Sets	Reps
Bench Press	1-3	10
Seated Press	1-3	10
Lat Pulls	1-3	10
Biceps curls	1-3	10
Triceps extensions	1-3	10
Curl-ups	1-3	25
Leg Presses	1-3	10
Leg Curls	1-3	10

 

 

References

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Ryan AS, Pratley RE, Elahi D and Goldberg AP. Resistive training increases fat-free mass and maintains RMR despite weight loss in postmenopausal women. J Appl Physiol  79: 818-823, 1995.

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Votruba SB, Horvitz MA and Schoeller DA. The role of exercise in the treatment of obesity. Nutrition 16: 179-188, 2000.